(i) Wavelength : The distance between two consecutive compressions (C) or two consecutive rarefactions (R) is called the wavelength, unit-metre.

(ii) Frequency : The number of oscillations per unit time is called frequency, unit-Hz.

(iii) Time period : The time taken by two consecutive compressions or rarefactions to cross a fixed point is called the time period.

(iv) Amplitude : The magnitude of the maximum disturbance in the medium on either side of the mean value is called the amplitude of the wave.